Moderate-intensity constant or high-intensity interval training? Metabolic effects on candidates to undergo bariatric surgery.

BACKGROUND & AIMS: Bariatric surgery is highly effective against obesity. Pre-surgical exercise programs are recommended to prepare the candidate physically and metabolically for surgery-related rapid weight loss. However, the ideal exercise prescription in this population is unknown. This study aimed to compare the metabolic effects of moderate-intensity constant (MICT) vs. a high-intensity interval training (HIIT) program in candidates to undergo bariatric surgery. METHODS AND RESULTS: Twenty-five candidates (22 women) to undergo sleeve gastrectomy aged from 18 to 60 years old were recruited. At baseline, we measured body composition, physical activity levels, grip strength, and aerobic capacity. Further, we assessed metabolic function through glycemia and insulinemia (both fasting and after oral glucose tolerance test (OGTT)), homeostatic model assessment for insulin resistance (HOMA-IR), lipid profile, glycated haemoglobin (HbA1c), transaminases, fibroblast growth factor 21 (FGF21), growth differentiation factor 15 (GDF15), apelin, and adiponectin. Afterward, participants were randomized into MICT (n = 14) or HIIT (n = 11). Both training programs consisted of 10 sessions (2-3 times/week, 30 min per session) distributed during 4 weeks before the surgery. After this, all outcomes were measured again at the end of the training programs and 1 month after the surgery (follow-up). A mixed effect with Tukey's post-hoc analysis was performed to compare values at baseline vs. post-training vs. postsurgical follow-up. Both training programs increased aerobic capacity after training (p < 0.05), but only after MICT these changes were kept at follow-up (p < 0.05). However, only MICT decreased fat mass and increased total muscle mass and physical activity levels (p < 0.05). Metabolically, MICT decreased insulinemia after OGTT (p < 0.05), whereas HIIT increased adiponectin after training and GDF15 at follow-up (both p < 0.05). CONCLUSIONS: Both MICT and HIIT conferred benefits in candidates to undergo bariatric surgery, however, several of those effects were program-specific, suggesting that exercise intensity should be considered when preparing these patients. Future studies should explore the potential benefits of prescribing MICT or HIIT in a customized fashion depending on a pretraining screening, along with possible summatory effects by combining these two exercise programs (MICT + HIIT). CLINICAL TRIAL REGISTRATION: International Traditional Medicine Clinical Trial Registry, N° ISRCTN42273422.

Kinesiología como Programa de Investigación. Una Reflexión respecto a Identidad / Physical therapy as a research program. Ideas regarding professional identity

La Kinesiología chilena ha tenido un desarrollo científico sostenido, particularmente durante las últimas décadas. Este desarrollo ha promovido progresivamente el posicionamiento de kinesiólogos y kinesiólogas como profesionales de la salud dentro de la comunidad, los cuales tienen como fundamento el estudio y aplicación de conocimiento relacionado al movimiento humano. Sin embargo, este desarrollo no ha sido azaroso, sino más bien ha respondido a la creciente actividad científica de los integrantes de la comunidad kinesiológica, además de la cada vez más indispensable utilización de información científica para la toma de decisiones clínicas. Por tanto, el presente artículo discute dos formas de analizar el desarrollo de las disciplinas científicas, y plantea que la kinesiología puede considerarse un programa de investigación, definición desde la cual se pueden analizar los desafíos actuales y futuros respecto al dinamismo necesario de la ciencia y el cómo la kinesiología se relaciona con otras disciplinas para potenciar su crecimiento, sin caer en la redundancia y/o repetición disciplinar.

The physical therapy in Chile has had sustained scientific development, particularly during the last decades. This development has progressively promoted the positioning of physical therapists as health professionals within the community, whose foundation is the study and application of knowledge related to human movement. However, this development has not been random, but rather has responded to the growing scientific activity of members of the physical therapy community, in addition to the essential use of scientific information for clinical decision making. Therefore, this article discusses two ways of analyzing the development of scientific disciplines and proposes that physical therapy can be considered a research program, a definition from which current and future challenges can be analyzed regarding the necessary dynamism of science, and how physical therapy relates to other disciplines to enhance their growth, without falling into professional redundancy and/or repetition.

Constant-moderate versus high-intensity interval training on heart adiponectin levels in high-fat fed mice: a preventive and treatment approach.

CONTEXT: Research has described that adiponectin plays a key role in cardiomyocytes metabolism, however, the effects of exercise during obesity on cardiac adiponectin levels is unclear. OBJECTIVE: To investigate the effects of constant-moderate endurance (END) and high-intensity interval training (HIIT), on heart adiponectin levels in mice. MATERIAL AND METHODS: Two experiments were conducted: (1) preventive (EX1): 10 week-old male mice were fed standard (CHOW) or high-fat diet (HFD;45% fat) and simultaneously trained with END and HIIT for 10 weeks; (2) Treatment (EX2): after 10 weeks of dietary intervention, another cohort of 10 week-old mice were trained by both programmes for 10 weeks. RESULTS: In EX1, END and HIIT decreased low-molecular weight adiponectin (∼0.5-fold; p < 0.05) and increased GLUT4 levels (∼2-fold; p < .05). In EX2, HFD significantly decreased high-molecular weight adiponectin (∼0.7-fold; p < .05), and END reversed this change.Discussion and conclusion: HFD and exercise influence heart adiponectin isoforms and therefore might impact cardiomyocyte metabolism.

Respuesta fisiológica al test de lanzadera en pacientes candidatos a cirugía bariátrica / Physiologic response to the incremental shuttle walk test in candidates to undergo bariatric surgery / Resposta fisiológica ao teste incremental de caminhada em candidatos a cirurgia bariátrica

Objetivos: la valoración de la tolerancia al ejercicio es clave para prescribir ejercicio en candidatos a cirugía bariátrica. El test de lanzadera (TL) se ha propuesto para este objetivo. Sin embargo, la evidencia que describe el rendimiento y respuesta fisiológica asociados a esta prueba en dicha población es escasa. El objetivo de este estudio fue describir la respuesta fisiológica a la realización del TL en candidatos a cirugía bariátrica. Métodos: este estudio transversal incluyó a 56 participantes. Se midieron factores antropométricos como la edad, peso, estatura y circunferencia de cintura, así como el nivel de actividad física espontáneo. Se valoró el rendimiento en el TL en metros, la respuesta fisiológica asociada en términos de frecuencia cardiaca de reserva (FCR) utilizada, presión arterial sistólica y diastólica, oximetría de pulso, sensación subjetiva al esfuerzo (SSE) y de fatiga de extremidades inferiores, antes y después del TL. Resultados: todos los participantes completaron la prueba sin complicaciones. Caminaron una mediana de 465 metros, equivalente al 61% de la distancia esperada. Utilizaron un 56% de la FCR, mientras que la SSE y fatiga de extremidades inferiores alcanzó valores 7/10 y 6/10 respectivamente. Fueron observadas asociaciones significativas entre el rendimiento en el TL vs factores antropométricos e indicadores de respuesta fisiológica. Conclusión: el TL es una prueba segura para valorar la tolerancia al esfuerzo en candidatos a cirugía bariátrica, la cual induce respuestas fisiológicas asociadas a intensidades moderadas. Se sugiere incluir esta prueba para la valoración de la condición física de estos sujetos.

Objective: Exercise tolerance measurement is key for exercise prescription in bariatric surgery candidates. Thus, the incremental shuttle walking test (ISWT) has been proposed as a useful tool for this purpose. However, reports describing the performance, and related physiological response, in candidates to bariatric surgery are scarce. Therefore, the aim of this study was to describe the physiological response of bariatric surgery candidates to the ISWT. Methods: This cross-sectional study included 56 participants. Anthropometric factors such as age, weight, height, and waist circumference were measured, as well as their spontaneous physical activity levels. Their ISWT performance was recorded, as well as the percentage of heart rate reserve used during the test, systolic and diastolic pressure, pulse oximetry, perceived exertion scale, and lower extremities fatigue, both before and after the ISWT. Results: All participants completed the test without complications. They walked a median of 465 meters, 61% of the expected distance. Heart rate reserve utilization reached 56%, while the perceived exertion rate and lower extremities fatigue reached 7/10 and 6/10, respectively. Moreover, significant associations between the ISWT performance vs anthropometric factors and physiological response outcomes were found. Conclusion: The ISWT is a safe and useful tool to assess exercise tolerance in bariatric surgery candidates, which induces physiological responses associated to moderate effort intensities. We suggest including the ISWT when assessing the physical performance of bariatric surgery candidates.

Objetivo: A medida da tolerância ao exercício é fundamental para a prescrição do exercício em candidatos à cirurgia bariátrica. Assim, o teste incremental de caminhada em vaivém (ISWT) tem sido proposto como uma ferramenta útil para este fim. No entanto, são escassos os relatos que descrevem o desempenho e a resposta fisiológica relacionada em candidatos à cirurgia bariátrica. Portanto, o objetivo deste estudo foi describir a resposta fisiológica do ISWT em candidatos à cirurgia bariátrica. Métodos: Este estudo transversal incluiu 56 participantes. Fatores antropométricos como idade, peso, altura, circunferência da cintura foram medidos, assim como os níveis de atividade física espontânea. O desempenho do ISWT foi registrado, assim como a porcentagem de reserva de frequência cardíaca utilizada durante o teste, pressão sistólica e diastólica, oximetria de pulso, escala de esforço percebido e fadiga de membros inferiores, tanto antes quanto após o ISWT. Resultados: Todos os participantes completaram o teste sem intercorrências. Eles caminharam uma mediana de 465 metros, o equivalente a 61% da distância esperada. A utilização de reserva de frequência cardíaca atingiu 56%, enquanto a taxa de esforço percebido e fadiga de membros inferiores atingiram 7/10 e 6/10, respectivamente. Além disso, foram encontradas associações significativas entre o desempenho do ISWT versus fatores antropométricos e os resultados da resposta fisiológica. Conclusão: O ISWT é uma ferramenta segura e útil para avaliar a tolerância ao exercício em candidatos à cirurgia bariátrica, que induz respostas fisiológicas associadas a intensidades moderadas de esforço. Sugerimos incluir o ISWT para avaliar o desempenho físico dos candidatos à cirurgia bariátrica.

Effects of exercise on irisin in subjects with overweight or obesity. A systematic review of clinical studies.

Introduction: Irisin is an adipomyokine involved in white adipose tissue browning, therefore, could be a key protein in metabolic health. However, exercise effects on irisin in subjects with overweight and/or obesity are conflicting. Therefore, this systematic review aims to search and analyse the literature available on this topic. From three databases: PubMed, ScienceDirect, and Medline, clinical studies published between 2010 and 2021 were considered. From 134 found, 14 studies were included. Only six reported plasma increases after exercise (~1.2 to 3-fold from pre-exercise levels). In addition, only 1 reported significant increases in skeletal muscle irisin mRNA levels (~2-fold). Also, irisin was measured from subcutaneous adipose tissue and saliva, where a ~2-fold increase in its protein levels was found in the latter. Exercise seems to increase the circulatory concentrations of irisin in subjects with overweight or obesity. However, this response is highly variable, therefore, a more integrative approach is urgently needed.

Introducción: La irisina es una adipomioquina relacionada a la transformación del tejido adiposo blanco a marrón, por tanto, podría ser una proteína clave para la salud metabólica. Sin embargo, los efectos del ejercicio sobre la irisina en personas con sobrepeso u obesidad son poco claros. Por lo anterior, esta revisión sistemática apunta a buscar y analizar la literatura disponible en este tema. Desde tres bases de datos: PubMed, ScienceDirect y Medline se buscaron estudios clínicos publicados entre el 2010 y 2021. De 134 estudios encontrados, 14 fueron incluidos. Solo 6 reportaron incrementos plasmáticos de irisina después del ejercicio (~1.2 a 3-veces respecto a niveles preejercicio). Además, solo 1 estudio describió incrementos significativos en el ARNm de irisina en el músculo esquelético (~2 veces sobre niveles preejercicio). La irisina también se medió desde tejido adiposo subcutáneo y saliva, encontrándose una elevación de (~2 veces sobre niveles preejercicio) en esta última. El ejercicio físico incrementaría las concentraciones circulatorias de irisina en personas con sobrepeso u obesidad. Sin embargo, esta respuesta es muy variable, por lo que se requiere una mirada más integrativa a la hora de estudiar este fenómeno.

Effects of exercise on irisin in subjects with overweight or obesity. A systematic review of clinical studies / Efectos del ejercicio sobre la irisina en personas con sobrepeso u obesidad. Una revisión sistemática de estudios clínicos

Irisin is an adipomyokine involved in white adipose tissue browning, therefore, could be a key protein in metabolic health. However, exercise effects on irisin in subjects with overweight and/or obesity are conflicting. Therefore, this systematic review aims to search and analyse the literature available on this topic. From three databases: PubMed, ScienceDirect, and Medline, clinical studies published between 2010 and 2021 were considered. From 134 found, 14 studies were included. Only six reported plasma increases after exercise (~1.2 to 3-fold from pre-exercise levels). In addition, only 1 reported significant increases in skeletal muscle irisin mRNA levels (~2-fold). Also, irisin was measured from subcutaneous adipose tissue and saliva, where a ~2-fold increase in its protein levels was found in the latter. Exercise seems to increase the circulatory concentrations of irisin in subjects with overweight or obesity. However, this response is highly variable, therefore, a more integrative approach is urgently needed. (AU)

La irisina es una adipomioquina relacionada a la transformación del tejido adiposo blanco a marrón, por tanto, podría ser una proteína clave para la salud metabólica. Sin embargo, los efectos del ejercicio sobre la irisina en personas con sobrepeso u obesidad son poco claros. Por lo anterior, esta revisión sistemática apunta a buscar y analizar la literatura disponible en este tema. Desde tres bases de datos: PubMed, ScienceDirect y Medline se buscaron estudios clínicos publicados entre el 2010 y 2021. De 134 estudios encontrados, 14 fueron incluidos. Solo 6 reportaron incrementos plasmáticos de irisina después del ejercicio (~1.2 a 3-veces respecto a niveles preejercicio). Además, solo 1 estudio describió incrementos significativos en el ARNm de irisina en el músculo esquelético (~2 veces sobre niveles preejercicio). La irisina también se medió desde tejido adiposo subcutáneo y saliva, encontrándose una elevación de (~2 veces sobre niveles preejercicio) en esta última. El ejercicio físico incrementaría las concentraciones circulatorias de irisina en personas con sobrepeso u obesidad. Sin embargo, esta respuesta es muy variable, por lo que se requiere una mirada más integrativa a la hora de estudiar este fenómeno. (AU)

Artrosis y discapacidad: un estudio desde el marco conceptual de la Clasificación Internacional del Funcionamiento, la Discapacidad y la Salud / Osteoarthritis and disability: A study from the conceptual framework of the International Classification of Functioning, Disability and Health

Introducción: La artrosis es una enfermedad reumatológica calificada y certificada en Chile a través de la Comisión de Medicina Preventiva y de Invalidez, conforme al marco de la Clasificación Internacional del Funcionamiento, la Discapacidad y la Salud; pero se desconoce cómo la discapacidad derivada de la artrosis se relaciona con indicadores de salud y sociodemográficos a nivel local. Objetivo: Investigar asociaciones entre variables relacionadas con la condición de salud, sociodemográficas y de calificación de discapacidad de las personas con diagnóstico de artrosis inscritas en el Registro Nacional de la Discapacidad en la Región de los Ríos, entre los años 2017-2019. Métodos: Estudio observacional, transversal, realizado de forma prospectiva y descriptiva en 427 personas con diagnóstico principal de artrosis. La muestra fue seleccionada de manera no probabilística desde la base de datos otorgada por la Comisión de Medicina Preventiva y de Invalidez de la región mencionada. Se utilizó el test de Chi-cuadrado y se consideró un resultado estadísticamente significativo si el valor de p < 0,05. Resultados: La muestra presentó predominantemente un grado leve de discapacidad y movilidad reducida, sexo femenino, 56-75 años de edad, casados, dueños de casa, con educación básica como máximo nivel alcanzado, residencia en zonas urbanas y adscritos al Fondo Nacional de Salud. Estas variables presentaron una asociación estadísticamente significativa con el grado de discapacidad. En variables vinculadas a la condición de salud, predominó la presencia de comorbilidades y la localización de artrosis en el miembro inferior. Hubo una asociación significativa entre el número de articulaciones afectadas y el grado de discapacidad. Conclusiones: Existe asociación entre los factores analizados y el grado de discapacidad. Los factores sociodemográficos presentaron una implicancia importante(AU)

Introduction: Osteoarthritis is a rheumatological disease that produces a significant impact in functionality on people who suffer from it, generating disability at different levels. This disability is measured and certified in Chile through the Commission for Preventive Medicine and Disability under criteria established in the framework of the International Classification of Functioning. However, it is unknown if sociodemographic indicators and the disability caused by osteoarthritis are related locally. Objective: To investigate associations between variables related to health condition, sociodemographic indicators, and disability index on people with a diagnosis of osteoarthritis registered in the National Disability Registry in the Los Rios Region between the years 2017 and 2019. Methods: Observational, cross-sectional study, carried out in a prospective and descriptive way in 427 people with osteoarthritis as a main diagnosis, registered in the National Disability Registry in the Los Rios Region. The sample was selected in a non-probabilistic way from the database provided by in the aforementioned region. The Chi-Squared test was used, and results were considered statistically significant if p < 0.05. Results: 53.9% of the participants presented a mild degree of disability and reduced mobility. 61.1% of the sample were female, predominantly between 56-75 years of age, married, homemakers, primary school as highest level of educational attainment, residence in urban areas, and registered with the National Health Fund. These variables presented show a statistically significant association with the degree of disability. As for those variables related to health condition, the presence of comorbidity and osteoarthritis located mainly in the lower limb predominated, and there was a significant association between the number of affected joints and the degree of disability. Conclusions: there is an association between the analyzed factors and the degree of disability, in which sociodemographic factors represented meaningful implications(AU)

Gestión, estrategias y adecuaciones educativas implementadas para una estudiante con discapacidad visual completa en la carrera de Kinesiología de la Universidad Austral de Chile: análisis de un caso / Management, strategies and educational adequations implemented for an undergraduate Kinesiology student with total visual disability of the Universidad Austral de Chile: analysis of a case

Introducción: La inclusión educativa es un desafío en la gestión del currículo de las instituciones de educación superior.Material y métodos.Informe de caso de una estudiante de Kinesiología con discapacidad visual que describe la gestión, las estrategias y las adecuaciones educativas implementadas.Resultados.Existió una variedad de adecuaciones educativas impulsadas por la gestión institucional. Deben implementarse actividades extraacadémicas y el quehacer autónomo.Conclusión.La gestión y las adecuaciones educativas permitieron, en gran medida, la participación de la estudiante en el proceso formativo universitario. (AU)

Introduction: Educational inclusion is a challenge in the management of the curriculum of higher education institution.Material and methods.Case report of a Kinesiology student with visual impairment that describes management, strategies and educational adjustments.Results.There was a variety of educational adjustments driven by institutional management. Extracurricular activities and autonomous work must be implemented.Conclusion.The management and educational adjustments greatly allowed the participation of the student in the university training process. (AU)

Effects of aerobic exercise on fibroblast growth factor 21 in overweight and obesity. A systematic review.

Fibroblast growth factor 21 (FGF21) has been suggested to improve metabolism during aerobic exercise in obesity. However, the variability of exercise interventions gives rise to discrepancies in the field. Therefore, we aimed to systematically review the available literature regarding the effects of aerobic exercise on FGF21 in the context of overweight and obesity. Our search included original articles published between 2009 and November 2021 found in PubMed, Science Direct, and Medline. Clinical and preclinical studies were included. Studies, where subjects or animals presented with other conditions (e.g., cancer, stroke), were excluded. From an initial 43 studies, 19 (clinical studies = 9; preclinical studies = 10) were eligible for inclusion in this review. The main findings were that acute exercise tended to increase circulatory levels of FGF21. In contrast, chronic exercise programs (≥4 weeks) had the opposite effect along with inducing mRNA and protein increases of FGF receptors and ß-klotho in adipose tissue, liver, and skeletal muscle. In conclusion, both clinical and preclinical studies showed that aerobic exercise exerts changes in circulatory and tissue FGF21, along with its receptors and co-receptor. Future research is needed to elucidate the mechanisms, along with the physiological and clinical implications of these changes.

Exercise induces favorable metabolic changes in white adipose tissue preventing high-fat diet obesity.

Diet and/or exercise are cost effective interventions to treat obesity. However, it is unclear if the type of exercise undertaken can prevent the onset of obesity and if it can act through different effects on fat depots. In this study we did not allow obesity to develop so we commenced the high-fat diet (HFD) and exercise programs concurrently and investigated the effect of endurance exercise (END) and high-intensity interval training (HIIT) on changes in cellular adipogenesis, thermogenesis, fibrosis, and inflammatory markers in three different fat depots, on a HFD and a chow diet. This was to assess the effectiveness of exercise to prevent the onset of obesity-induced changes. Mice fed with chow or HFD (45% kcal fat) were trained and performed either END or HIIT for 10 weeks (3 x 40 min sessions/week). In HFD mice, both exercise programs significantly prevented the increase in body weight (END: 17%, HIIT: 20%), total body fat mass (END: 46%, HIIT: 50%), increased lean mass as a proportion of body weight (Lean mass/BW) by 14%, and improved insulin sensitivity by 22%. Further evidence of the preventative effect of exercise was seen significantly decreased markers for adipogenesis, inflammation, and extracellular matrix accumulation in both subcutaneous adipose tissue (SAT) and epididymal adipose tissue (EPI). In chow, no such marked effects were seen with both the exercise programs on all the three fat depots. This study establishes the beneficial effect of both HIIT and END exercise in preventing metabolic deterioration, collagen deposition, and inflammatory responses in fat depots, resulting in an improved whole body insulin resistance in HFD mice.

Blockade of High-Fat Diet Proteomic Phenotypes Using Exercise as Prevention or Treatment.

The increasing consumption of high-fat foods combined with a lack of exercise is a major contributor to the burden of obesity in humans. Aerobic exercise such as running is known to provide metabolic benefits, but how the overconsumption of a high-fat diet (HFD) and exercise interact is not well characterized at the molecular level. Here, we examined the plasma proteome in mice for the effects of aerobic exercise as both a treatment and as a preventative regimen for animals on either a HFD or a healthy control diet. This analysis detected large changes in the plasma proteome induced by the HFD, such as increased abundance of SERPINA7, ALDOB, and downregulation of SERPINA1E and complement factor D (CFD; adipsin). Some of these changes were significantly reverted using exercise as a preventative measure but not as a treatment regimen. To determine if either the intensity or duration of exercise influenced the outcome, we compared high-intensity interval training and endurance running. Endurance running slightly outperformed high-intensity interval training exercise, but overall, both provided similar reversion in abundance of plasma proteins modulated by the HFD, including SERPINA7, apolipoprotein E, SERPINA1E, and CFD. Finally, we compared the changes induced by overconsumption of a HFD with previous data from mice fed on an isocaloric high-saturated fatty acid or polyunsaturated fatty acid diet. This identified several common changes, including not only increased apolipoprotein C-II and apolipoprotein E but also highlighted changes specific for overconsumption of a HFD (fructose-bisphosphate aldolase B, SERPINA7, and CFD), saturated fatty acid-based diets (SERPINA1E), or polyunsaturated fatty acid-based diets (haptoglobin). Together, these data highlight the importance of early intervention with exercise to revert HFD-induced phenotypes and suggest some of the molecular mechanisms leading to the changes in the plasma proteome generated by HFD consumption. Web-based interactive visualizations are provided for this dataset (larancelab.com/hfd-exercise), which give insight into diet and exercise phenotypic interactions on the plasma proteome.

[Relationship between fibroblast growth factor-21, muscle mass, and function outcomes in overweight and obese older adults living in the community. An exploratory study]. / Relación del factor de crecimiento de fibroblastos 21 con indicadores de masa y función muscular en personas mayores con sobrepeso u obesidad. Estudio exploratorio.

BACKGROUND: Age-related decreases in muscle mass and function are associated with the development of metabolic impairments, particularly in the context of obesity. Fibroblast growth factor21 (FGF-21) has been suggested as a common mediator of both processes. No known studies have examined the association between FGF-21 and muscle mass and function in overweight or obese older adults. With this in mind, this study aimed to investigate the association between plasma levels of FGF-21 and muscle mass and function outcomes in overweight or obese older adults. MATERIALS AND METHODS: Exploratory study, which included 39 adults of 60-70years old with body mass indexes >25kg/m2. As study outcomes, measurements were made of appendicular muscle mass (AMM), grip strength, 5 times sit-to-stand test (5xSTT), as well as plasma levels of FGF-21, fasting glucose, and insulin. The homeostatic model assessment index (HOMA-IR) was also calculated to determine the presence of insulin resistance. RESULTS: Significant relationships were found between plasma levels of FGF-21 vs 5xSTT (rho=0.49; P<.05). Moreover, FGF-21 levels were significantly higher in those with insulin resistance (P<.05), as well as with having lower levels of AMM (P<.05). CONCLUSION: There is a relationship between the plasma levels of FGF-21 and muscle function outcomes in overweight or obese older adults. Future studies should investigate the potential causalities between these relationships.

Effect of exercise on hepatic steatosis: Are benefits seen without dietary intervention? A systematic review and meta-analysis.

BACKGROUND: Interventions involving both exercise and dietary modification are effective in reducing steatosis in nonalcoholic fatty liver disease (NAFLD). However, exercise alone may reduce liver fat and is known to have other positive effects on health. The primary aim of this study was to systematically review the effect of exercise alone without dietary intervention on NAFLD and to examine correlations across changes in liver fat and metabolic markers during exercise. METHODS: Relevant online databases were searched from earliest records to May 2020 by two researchers. Studies were included where the trial was a randomized controlled trial, participants were adults, exercise intervention was longer than 4 weeks, no dietary intervention occurred, and the effect of the intervention on liver fat was quantified via magnetic resonance imaging/proton magnetic resonance spectroscopy. RESULTS: Of 21 597 studies retrieved, 16 were included involving 706 participants. Exercise was found to have a beneficial effect on liver fat without dietary modification (-2.4%, -3.13 to -1.66) (mean, 95% CI). Pearson correlation showed significant relationships between change in liver fat and change in weight (r = 0.67, P = .007), liver enzymes aspartate aminotransferase (r = 0.76, P = .002) and alanine aminotransferase (r = 0.91, P < .001), and cardiorespiratory fitness VO2 peak (peak volume oxygen consumption) (r = -0.88, P = .004). By multivariate regression, change in weight and change in VO2 peak significantly contributed to change in liver fat (R2 = 0.84, P = .01). CONCLUSIONS: This systematic review found that exercise without dietary intervention improves liver fat and that clinical markers may be useful proxies for quantifying liver fat changes.

Demographic/anthropometric factors and physiological performance-related parameters associated with the six-minute walk test in bariatric surgery candidates, from Valdivia, Chile / Fatores demográficos/antropométricos e parâmetros fisiológicos relacionados ao desempenho associados ao teste de caminhada de seis minutos em candidatos à cirurgia bariátrica, de Valdivia, Chile / Factores demográficos/antropométricos y parámetros fisiológicos relacionados con el desempeño en la prueba de la marcha de seis minutos de candidatos a cirugía bariátrica de Valdivia, Chile

ABSTRACT The six-minute walk test (6MWT) is widely used to measure functional capacity in special populations. However, the factors associated with its performance in candidates for bariatric surgery are unclear. Therefore, this study aimed to investigate the influence of anthropometric and physiological factors in the 6MWT performance in bariatric surgery candidates. This cross-sectional study included 107 candidates for bariatric surgery. Anthropometric factors considered: gender, weight, height, body mass index (BMI), waist-to-hip, and waist-to-height ratios. Along with distance covered during 6MWT, physiological factors such as ratings of perceived exertion (RPE) and heart rate reserve percentage used (%HRR) were recorded. Among the 107 patients (mean age: 39.6 years), 83 volunteers were accepted to perform the 6MWT. No gender differences were observed in terms of distance covered, %HRR, and RPE during the 6MWT. Moreover, BMI and %HRR explained 21% of the 6MWT distance covered. Furthermore, participants with BMI ≤41.5 kg/m2 walked ~50 meters more than their peers above this level (p=0.05). Interestingly, heart rate increase during the 6MWT was lower than described for healthy populations. BMI and %HRR partially explain the variability of the 6MWT performance in bariatric surgery candidates.

RESUMO O teste de caminhada de seis minutos (TC6) é uma ferramenta amplamente usada para medir a capacidade funcional em populações especiais. No entanto, os fatores associados ao seu desempenho em candidatos à cirurgia bariátrica não são claros. Portanto, o objetivo deste estudo foi investigar a influência de fatores antropométricos e fisiológicos no desempenho do TC6 em candidatos à cirurgia bariátrica. Este estudo transversal incluiu 107 candidatos à cirurgia bariátrica. Os fatores antropométricos incluíram: sexo, peso, altura, índice de massa corporal (IMC) e índices cintura-quadril e altura-cintura. Além da distância percorrida durante o TC6, foram registrados fatores fisiológicos, como sensação subjetiva de esforço (SSE) e a porcentagem de frequência cardíaca de reserva utilizada (% FCR). Dos 107 pacientes (idade média: 39,6 anos), 83 voluntários concordaram em realizar o TC6. Não foram observadas diferenças por sexo em termos de distância percorrida, % FCR e SSE durante o TC6. Além disso, IMC e% FCR explicaram 21% da distância percorrida no TM6M. Além disso, indivíduos com IMC≤41,5 kg/m2 andaram ~50 metros a mais do que seus pares acima desse nível (p=0,05). Curiosamente, os aumentos na frequência cardíaca durante o TC6 foram inferiores aos descritos em populações saudáveis. IMC e %FCR foram fatores que explicaram parte da variabilidade do desempenho da TC6 em candidatos submetidos à cirurgia bariátrica.

RESUMEN La prueba de la marcha de seis minutos (PM6) es una herramienta muy utilizada para medir la capacidad funcional en ciertas poblaciones. Sin embargo, poco se conoce sobre los factores asociados a su desempeño en candidatos a cirugía bariátrica. Ante esto, el objetivo de este estudio fue evaluar la influencia de factores antropométricos y fisiológicos en el desempeño de la PM6 en candidatos a cirugía bariátrica. En este estudio transversal participaron 107 candidatos a cirugía bariátrica. Los factores antropométricos fueron: sexo, peso, altura, índice de masa corporal (IMC) e índices cintura-cadera y altura-cintura. Además de la distancia recorrida durante la PM6, se registraron los factores fisiológicos como la sensación subjetiva de esfuerzo (SSE) y el porcentaje de frecuencia cardíaca de reserva utilizada (% FCR). De los 107 pacientes (edad media: 39,6 años), 83 voluntarios aceptaron realizar la PM6. No se encontraron diferencias por sexo respecto de la distancia recorrida, % FCR y ESS durante la PM6. Además, el IMC y el % FCR explicaron el 21% de la distancia recorrida en la PM6. Y los individuos con un IMC ≤41,5 kg/m2 caminaron ~50 metros más que sus pares por encima de este nivel (p=0,05). Resultó interesante que el incremento de la frecuencia cardíaca durante la PM6 fue más bajo que los reportados en poblaciones sanas. El IMC y % FCR fueron los factores que explicaron parte de la variabilidad en el desempeño de la PM6 en candidatos a cirugía bariátrica.

Effect of High-Intensity Interval Training on Glycemic Control in Adults With Type 1 Diabetes and Overweight or Obesity: A Randomized Controlled Trial With Partial Crossover.

OBJECTIVE: To study the effect of 12 weeks of high-intensity interval training (HIIT) on glycemic control in adults with type 1 diabetes and overweight or obesity. RESEARCH DESIGN AND METHODS: Thirty inactive adults with type 1 diabetes who had BMI ≥25 kg/m2 and HbA1c ≥7.5% were randomized to 12 weeks of either HIIT exercise intervention consisting of 4 × 4-min HIIT (85-95% peak heart rate) performed thrice weekly or usual care control. In a partial crossover design, the control group subsequently performed the 12-week HIIT intervention. The primary end point was the change in HbA1c from baseline to 12 weeks. Glycemic and cardiometabolic outcomes were measured at 0, 12, and 24 weeks. RESULTS: Participants were aged 44 ± 10 years with diabetes duration 19 ± 11 years and BMI 30.1 ± 3.1 kg/m2. HbA1c decreased from 8.63 ± 0.66% at baseline to 8.10 ± 1.04% at 12 weeks in the HIIT intervention group (P = 0.01); however, this change was not significantly different from the control group (HIIT -0.53 ± 0.61%, control -0.14 ± 0.48%, P = 0.08). In participants who undertook at least 50% of the prescribed HIIT intervention, the HbA1c reduction was significantly greater than control (HIIT -0.64 ± 0.64% [n = 9], control -0.14 ± 0.48% [n = 15], P = 0.04). There were no differences in insulin dose, hypoglycemia on continuous glucose monitoring, blood pressure, blood lipids, body weight, or body composition between groups. CONCLUSIONS: Overall, there was no significant reduction in HbA1c with a 12-week HIIT intervention in adults with type 1 diabetes. However, glycemic control may improve for people who undertake HIIT with greater adherence.

Skeletal muscle adiponectin induction in obesity and exercise.

Recent scientific efforts have focused on the detrimental effects that obesity has on the metabolic function of skeletal muscles and whether exercise can improve this dysfunction. In this regard, adiponectin, with important metabolic functions (e.g. insulin-sensitizer and anti-inflammatory), has been recently described as a myokine that acts in an autocrine/paracrine manner. Earlier studies reported that muscle adiponectin could be induced by pro-inflammatory mediators (e.g. lipopolysaccharide), cytokines, and high-fat diets, providing a protective mechanism of this tissue against metabolic insults. However, when metabolic insults such as high-fat diets are sustained this protective response becomes dysregulated, making the skeletal muscle susceptible to metabolic impairments. Recent studies have suggested that exercise could prevent or even reverse this process. Considering that most scientific knowledge on adiponectin dysregulation in obesity is from the study of adipose tissue, the present review summarizes and discusses the literature available to date regarding the effects of obesity on skeletal muscle adiponectin induction, along with the potential effects of different exercise prescriptions on this response in an obesity context.

Constant-Moderate and High-Intensity Interval Training Have Differential Benefits on Insulin Sensitive Tissues in High-Fat Fed Mice.

In a mouse model of diet-induced obesity, this study determined if two exercise prescriptions with equivalent time and distance covered, [constant-moderate endurance (END) and high intensity interval training (HIIT)], exert differential metabolic benefits on insulin sensitive tissues. Male 10 week old C57BL/6 mice were fed a high fat diet (HFD; 45% kcal fat) ad libitum for 10 weeks and for a further 10 weeks they underwent END or HIIT training (3 × 40 min sessions/wk). Untrained HFD and chow-fed mice acted as controls. At 30 weeks of age, mice were sacrificed and quadriceps muscle, subcutaneous adipose tissue (SAT) and liver were excised. Neither END nor HIIT altered body weight or composition in HFD mice. In quadriceps, HFD decreased high-molecular weight adiponectin protein, which was normalized by END and HIIT. In contrast, HIIT but not END reversed the HFD-driven decrease in the adiponectin receptor 1 (AdipoR1). In SAT, both programs tended to decrease collagen VI protein (p = 0.07-0.08) in HFD, whereas only HIIT induced an increase in the mRNA (3-fold vs. HFD untrained) and protein (2-fold vs. HFD untrained) of UCP1. In liver, only END reversed collagen I accumulation seen in HFD untrained mice. Our results suggest that HIIT may promote better systemic metabolic changes, compared to END, which may be the result of the normalization of muscle AdipoR1 and increased UCP1 seen in SAT. However, END was more effective in normalizing liver changes, suggesting differential metabolic effects of END and HIIT in different tissues during obesity.

Skeletal muscle adiponectin induction depends on diet, muscle type/activity, and exercise modality in C57BL/6 mice.

Changes in skeletal muscle adiponectin induction have been described in obesity and exercise. However, whether changes are consistent across muscle types and with different exercise modalities, remain unclear. This study compared the effects of diet and two isocaloric training programs on adiponectin induction and its regulators in three muscles: quadriceps (exercising/glycolytic-oxidative), gastrocnemius (exercising/glycolytic), and masseter (nonexercising/glycolytic). Ten-week-old male C57BL/6 mice were fed a high-fat diet (HFD) (45% fat) or standard CHOW diet (12% fat) ad libitum and underwent one of two training regimes: (1) constant-moderate training (END), or (2) high intensity interval training (HIIT) for 10 weeks (3 × 40 min sessions/week). Chow and HFD-fed untrained mice were used as control. Compared with Chow, HFD induced an increase in protein levels of low-molecular weight (LMW) adiponectin in gastrocnemius and masseter (~2-fold; P < 0.05), and a decrease of high-molecular weight adiponectin (HMW-most bioactive form) in quadriceps (~0.5-fold; P < 0.05). Only END prevented these changes (P < 0.05). HFD induced a decrease of adiponectin receptor 1 (AdipoR1) protein in exercising muscles of untrained mice (~0.5-0.8-fold; P < 0.05); notably, END also decreased AdipoR1 protein levels in lean and HFD mice. This type of training also normalized HFD-driven mRNA changes found in some adiponectin downstream factors (sirtuin 1, Pgc-1a, and Ucp2) in the three muscles tested. Our results indicate that diet, muscle type/activity, and exercise modality influences muscle adiponectin profile, and some of its mediators. These parameters should be taken into consideration when investigating this endocrine response of the skeletal muscle, particularly in the context of obesity and metabolic disorders.

Differential metabolic effects of constant moderate versus high intensity interval training in high-fat fed mice: possible role of muscle adiponectin.

Exercise regimens may have differing effects in the presence of obesity. In addition to being fat derived, adiponectin has recently been described as a myokine that regulates insulin sensitivity, which may link to exercise-related metabolic benefits in obesity. Whether skeletal muscle adiponectin varies in different exercise modalities is unclear. This study investigated the comparative effects of 10 weeks of endurance constant-moderate intensity exercise (END) with high intensity interval training (HIIT), on metabolic outcomes, including muscle adiponectin in a mouse model of diet-induced obesity. Ten-week-old male C57BL/6 mice were fed a high-fat diet (HFD) (45% FAT) or standard CHOW diet ab libitum and underwent one of three training regimes: (1) no exercise, (2) END, or (3) HIIT (8 bouts of 2.5 min with eight periods of rest of 2.5 min) for 10 weeks (3 × 40 min sessions/week). Chow-fed mice acted as controls. Compared with HFD alone, both training programs similarly protected against body weight gain (HFD = 45 ± 2; END = 37 ± 2; HIIT = 36 ± 2 g), preserved lean/fat tissue mass ratio (HFD = 0.64 ± 0.09; END = 0.34 ± 0.13; HIIT = 0.33 ± 0.13), and improved blood glucose excursion during an insulin tolerance test (HFD = 411 ± 54; END = 350 ± 57; HIIT = 320 ± 66 arbitrary units [AU]). Alterations in fasting glycemia, insulinemia, and AST/ALT ratios were prevented only by END. END, but not HIIT increased skeletal muscle adiponectin mRNA (14-fold; P < 0.05) and increased protein content of high molecular weight (HMW) adiponectin (3.3-fold), whereas HIIT induced a milder increase (2.4-fold). Compared with HFD, neither END nor HIIT altered circulating low (LMW) or high (HMW) molecular weight adiponectin forms. Furthermore, only END prevented the HFD downregulation of PGC1α (P < 0.05) mRNA levels downstream of muscle adiponectin. These data show that different training programs affect muscle adiponectin to differing degrees. Together these results suggest that END is a more effective regimen to prevent HFD-induced metabolic disturbances in mice.